Aircraft passenger boarding bridges provide a weatherproof enclosure for passengers moving between an airport terminal building and the doorway of an aircraft. Typically the inner end of the bridge communicates with the airport terminal building and the outer end of the bridge provides a cab having a closure curtain adapted to engage an aircraft and form a weather tight seal therewith.
Inasmuch as the exterior surfaces of aircraft fuselages are convex in shape at the passenger doorways thereof, the outer ends of the closure curtains must be sufficiently flexible to conform to the exterior aircraft surface. An example of an aircraft closure curtain having a flexible forward end adapted to engage the convex surface of an aircraft surrounding a doorway may be seen in U.S. Pat. No. 3,644,952 to Hatch.
Typical aircraft closure curtains include a support frame, fabric mounted on the frame, resilient pads at the end of the curtain adapted to engage the aircraft and an actuator mechanism which moves the closure curtain towards and away from an aircraft doorway. In this structure the resilient pads and the fabric are wear items which must be replaced periodically as part of the maintenance of an aircraft passenger boarding bridge. Conventionally, the fabric portion of an aircraft closure curtain is installed in the field subsequent to the frame being mounted on the cab of a bridge. In most instances the closure curtain frame is affixed to the bridge cab at the factory. This requires the curtain fabric to be lifted above the frame, unfolded, positioned and secured to the frame from a distance of between 12 and 20 feet in the air. The positive restraint straps or safety straps that contain the movement of the curtain must be removed to allow access to the top horizontal frame components. This requires the frame to be otherwise spaced and supported during removal and/or installation of the fabric. During this procedure the fabric joints undergo stresses much higher than those experienced during operation. It has been found the premature failure of fabric curtain joints are directly attributed to stresses occurred during installation. Additionally, integrating the frame with the bridge cab structure makes shipping the structure bulky and cumbersome.
Thus, it is desirable to provide an aircraft closure curtain that does not require the frame to be preassembled to the aircraft passenger boarding bridge and the curtain to be installed with the frame in place on the bridge. It has been found desirable to provide an aircraft closure curtain having a frame and fabric subassembly that may be shipped and installed as an integral unit.
It also has been found desirable to provide an aircraft closure curtain having horizontal frame components which may be detached from vertical frame components. This provides for ease of curtain replacement and allows the vertical frame components to be folded parallel with the horizontal frame components with the curtain installed to provide a compact shipping package.